Progress in optical interconnects for harsh environments

Abstract

Growing demands in high data capacity and low energy consumption have driven the development of high-performance optical interconnects for many commercial applications, such as links for long-haul, intra-/inter-datacenter, and 5G communication. Typically, the photonic devices used in these environments are optimized for operation at or above room temperature, however there is an existing and growing need for optimized photonic devices to operate in cryogenic and/or high-radiation environments. Applications of these optical interconnects range from control and readout from superconducting integrated circuits for quantum computing, to readout of tracking detectors in high-energy physics (HEP) particle accelerators, to readout of next-generation infrared (IR) focal plane array (FPA) detectors. Key to the success of these optical interconnects is the high-performance and ruggedization of the electro-optic modulator (EOM), typically implemented either as a remoted external device or as a directly modulated light source. The underlying semiconductor physics models of the EOM must account for the conditions presented by the harsh environment, leading to optimization challenges at both device and link levels. The current state of the art of optical interconnects for harsh environments will be reviewed, highlighting the current challenges and opportunities, in addition to presenting an outlook on the technology development trends and enabling applications.